cattrs is an open source Python library for structuring and
unstructuring data. cattrs works best with attrs classes, dataclasses
and the usual Python collections, but other kinds of classes are
supported by manually registering converters.

Python has a rich set of powerful, easy to use, built-in data types
like dictionaries, lists and tuples. These data types are also the
lingua franca of most data serialization libraries, for formats
like json, msgpack, yaml or toml.

Data types like this, and mappings like dict s in particular,
represent unstructured data. Your data is, in all likelihood,
structured: not all combinations of field names or values are valid
inputs to your programs. In Python, structured data is better
represented with classes and enumerations. attrs is an excellent
library for declaratively describing the structure of your data,
and validating it.

When you're handed unstructured data (by your network, file system,
database...), cattrs helps to convert this data into structured data.
When you have to convert your structured data into data types other
libraries can handle, cattrs turns your classes and enumerations
into dictionaries, integers and strings.

Homepage:
https://github.com/python-attrs/cattrs
